Sealing means for galvanic cell casings



July 15, 1958 P. A. c. JACQUIER SEALING MEANS FOR GALVANIC CELL CASINGS'Filed Feb. 26, 1967 2 Sheets-Sheet 1 A m m w IZL WIIIII/IIIIIIIIYIA.

INVENTOR. Wm AC ATTORNEYS July 15, 1958 RA. c. JACQUIER ,6

SEALING MEANS FOR GALVANIC CELL CASINGS Filed Feb. 26, 1957 2Sheets-Sheet 2 ATTORNEYS United States Patent SEALING MEANS FOR GALVANICCELL CASINGS Pierre A. C. Jacquier, Paris, France, assignor to Societedes Accumulateurs Fixes et de Traction (Societe Anonyme), Romainville,France, a French company Application February 26, 1957, Serial No.642,622

Claims priority, application France March 12, 1956 6 Claims. (Cl.136-111) This invention relates to galvanic cells and more particularlyto improved means for securing fluid-tight casings therefor.

Galvanic cells (either primary or secondary) enclosed in fluid-tightusually disc-shape casings are already known in the art, said casingscomprising usually a metal bottom and a metal lid deeply fitted intoeach other and separated by a tight insulating gasket. The bottom andthe lid constitute the two terminals of the cell.

It is also known that it is very difiicult to obtain complete tightnessand seals with such casings. This difficulty causes numerousdisadvantages such as leakage of corrosive electrolyte,short-circuiting, rapid cell deterioration and the like.

An object of the present invention is the provision of a galvanic cellcasing construction providing improved sealing tightness and alsoimproved insulating properties as compared with existing structures.

Other objects and features of the invention are the provision of simplecasing structures that are readily assembled and effectively and easilysealed during assembly.

Further objects and features of the invention will become apparent fromthe following specification and accompanying drawings wherein:

Figure 1 shows in section an electro-chemical cell embodying one form ofthe invention;

Figure 2 shows on an enlarged scale, a selected portion of Figure l inan initial assembly stage;

Figure 3 shows the same parts after completion of assembly;

Figure 4 is a detailed section of another embodiment of the invention;

Figure 5 is a detailed fragmentary section of a further embodiment ofthe invention in an initial assembly stage; and

Figure 6 shows the parts of Figure 5 after completion of assembly.

According to one embodiment of the invention, the side wall of the metalbottom member of the casing is covered with and encased in asubstantially U-sectioned resilient, tight bushing one of whose legsextends to the full inside depth of the side and the other of whose legsis longer than the outside depth of said side edge. The U-bend of thebushing rides on the rim of said side wall. The internal face of the lidmember which is mounted onto the said bottom comes into abutting contactwith the bushing covered rim of said bottom, while the rim portion ofthe lid is obliquely turned down or crimped onto the external face ofthe bottom.

Preferably the external leg of the tight U-shaped bushing has athickness which increases from the U-bend to its free edge. Also atleast one of the two parts of the casing, either the bottom or the lid,has an outwardly spread bell shape or flare for receiving thisincreasingly thick bushing leg.

In this way, turn down of the lid is effected upon a thicker part of thebushing so that the material of said thicker part is pressed back intothe space comprised by the side wall of the bottom and the side wall ofthe lid and maintained under compression. This compression cooperates inmaintaining tightness of seal.

Referring to the drawings and first to Figures 1 to 3, inclusive, thecell includes a casing 10, comprising a bottom member 11 and a lidmember or cover 12 both of metallic material. This casing on assemblycontains conventional positive and negative active materials 13 and 14and, for example, an electrolyte-saturated separator The side wall 16 ofthe bottom is encased or enveloped about its entire periphery and to thefull extent of its depth by an insulating tight U-sectioned bushing 17of any desirable, preferably resilient, insulating material. The U-bend17a as shown extends over and covers or rides on the upper edge or rimof the side wall 16 as shown in Figures 1, 2 and 3. The bottom 11 hasthe shape of a truncated cone with the sloping wall portion 18.

In its initial shape as shown in Figure 2, the outer leg 17b of theU-shaped bushing 17 increases inthickness outwardly away from the U-bend17a.

As seen in Figure 2, the side wall 19 of the lid 12 flares downwardlyand outwardly to facilitate mounting of the lid 12 on the bushingcarrying bottom 11. The said wall 19 additionally is longer than theside wall 16 of the bottom 11.

In assembly, the bottom 11 is filled successively with active material14, separator 15, active material 13 after the bushing 17 has beenmounted on the side wall 6. The lid 12 is then mounted over the bottomas shown in Figure 2 so that its side wall 19 encloses the bushing leg17b. The bottom 11 and the lid 12 are then pressed tightly together andwhile this pressure is maintained, the lower peripheral edge 19a of thelid 12 is crimped or turned down onto the sloping wall 18 of the bottom11 as illustrated inFigures l and 3. The crimping action presses thelower rim 19a of the lid tightly against the sloping wall portion 18 ofthe bottom 17 and compresses the thickened wall 17a of the bushing 17into the space comprised between the walls 16 and 19. This compressioncauses perfect filling of the said space. Moreover it is permanentlymaintained in this condition so that the compressed bushing effectivelyseals the contents enclosed within the bottom 11 and the lid 12 formingthe cell. Moreover, the crimping tends to force the upper edge of thewall 16 towards the inner face of the lid 12 compressing the portion 17aof the bushing. in this Way, the bushing provides a double-sealingeffect first at the region of its compressed portion 17a and secondly atthe compressed region 17b between the walls 16 and 19.

The arrangement of Figure 4 shows modification in the side walls of thebottom and of the lid. In this embodiment the bottom 20 has an upwardlyoutwardly flaring or bell shaped side wall 21 while the lid 22 has aninitially cylindrical unflared side wall 23. The U-sectioned bushing 24is substantially similar to the bushing 17, its

riphery of the bottom 20. These two steps energetically press the upperedge of bottom wall 21 toward the inner face of lid 22 compressingbushing portion 24a and also push the bushing leg 24b into the spacedefined between the walls 21 and 23 compressing it tightly. Thiscompression is maintained by the crimped edge 23a. Double sealing occursas a result of the compressions of portions 243a and leg 24b of thebushing.

In the embodiment shown in Figures and 6, provision is made for stillbetter cell tightness and sealing of the assembled bottom and lid, andin addition for still better insulation of the positive and negativeactive materials within the cell. In the embodment one feature ofimprovement resides in providing the lid member on its inner face with aperipheral groove in which the !Jbend of the bushing and partially therim of the side wall of the bottom member are lodged. As a result, therim is maintained in said groove and the side wall of said bottom memberis prevented from bending inwardly away mm the side wall of the lid.Additionally the U-bend of the bushing fills the groove substantiallyand being under compression insures a tight seal.

In addition to this as another feature, the inner leg of the bushingdoes not extend the full depth of the side wall of the bottom. Itextends only to the level of the separator and is provided with aperipheral flange which is pressed against the separator duringassembly. With this arrangement complete separation is obtained betweenthe positive and negative compartments of the cell, between which thereis no communication except through the separator.

Referring to the Figures 5 and 6, the cell casing 3%, comprises a bottommember 31 and a lid member or cover 32 both of metallic material. Thiscasing on assembly contains positive and active materials 33 and 34 and,for example, an electrolyte-saturated separator 35.

The side wall 36 of the bottom member 31 is encased or enveloped aboutits entire outer periphery and to a partial extent of its internal depthby an insulating tight U-sectioned bushing 37 of any desirable,preferably resilient, insulating material. The U-bend 37a extends overand rides on and covers the upper rim of the side wall 36. The bottommember 31 has the shape of a truncated cone with the sloping wallportion 33.

in its initial shape the outer leg 37b of the U-shaped bushing 37increases in thickness outwardly away from the U-bend 37a. The inner leg370 of the bushing has a peripheral flange 37d at its rim for purposesto be described.

The side wall 39 of the lid 32 initially flares downwardly and outwardlyto facilitate mounting of the lid member 32 on the bushing carryingbottom member 31. The said wall 3% additionally is longer than the sidewall 36.

An annular peripherally located groove is provided on the inner face ofthe lid member 32, for example, by stamping an annular gorge 41 in lid32 from its outer surface at a short distance from the periphery of thelid. This groove 40 may be fabricated in other ways, for example, bydepressing the entire rnid-portion of lid member 32 although thisalternative is not advantageous if the cells are to be stacked forseries connection.

The active material 34 fits into the bottom member 31 and is covered bythe electrolyte-saturated separator 35 which has the same diameter asthe inner diameter of wall 36. The upper surface separator 35 lies justbelow the peripheral flange 37d which rests upon it. The active material33 has an annular peripheral groove 42 to receive the flange 37d and hasa thickness such that on assembly of the lid member 32 with the filledbottom member 31, the upper surface of active material 33 lies spacedfrom the inner surface of the lid member 32 and the outer surface of theU-bend 37a of the bushing lies engaged within the groove 4-0 as is seenin Figure 5.

For completion of assembly, the lid member 32 and bottom member 31 arepressed together bringing the inner surface of lid member 32 intosurface contact with the active material 33 and firmly compressing thematerial in the U-bend 37a of the bushing 37 within the groove 40 underpressure of the upper rim or edge of wall 36. The lower edge 39a of lidwall 39 is then crimped to apply it tightly against the conical wall 38of the bottom member 31, compressing the lower edge of leg 37b betweenthem. The crimping drives the lid member more deeply over the bottommember 31 and insures complete surface contact between the lid member 32and active material 33. At the same time, the rim of side wall 36 of thebottom member 31 is pushed into the groove 453 so that said side wallcannot be bent inwardly by further tightening pressure. it 1C'f JOV3lfmaterial of the U-bend 37a is tightly jammed and compressed in thegroove 40 wholly filling any free space there, some part of the elasticmaterial even spreading inwardly at 43 as seen in Figure 6. Moreover theflange 37d of the bushing is jammed tightly 2 inst surface of theseparator 35 so that the comp ment containing the active material 34 hasno communication with the compartment containing active material 33except through the separator 35. In this way migration of activematerial from one compartment to the other along the internal walls ofthe bottom member 3 is prevented.

With the arrangement of Figures 5 and 6, a very tight union is effectedbetween the lid member and bottom member. Moreover, it is to be notedthat the rim of the bushing which lies gripped between the tapered wall38 of the bottom 31 and the crimped or turned down rim 39a of the lid 32constitutes an autoclave joint. Any gaseous pressure appearing in thecasing tends to increase the tightening and sealing at this gripped partof the bushing. The same remark applies to the other above-mentionedembodiments of the invention.

While specific embodiments of the invention have been described andshown, variations in structural detail within the scope of the appendedclaims are possible and are contemplated. There is no intentiontherefore of limitation to the exact details described and shown.

What is claimed is:

l. A substantially leak-proof casing for a galvanic cell comprising abottom member and a lid member having a side wall fitted one into theother, said bottom member having a side wall, a substantially invertedU-sectioned insulating bushing mounted on said side wall with its U-bendriding on the rim of said wall, said bushing having its outermost legincreasing outwardly in thick- .ess from the U-bend, said lid memberhaving its rim portion turned down against said bottom member tocompress said leg of said bushing between the side walls and also tocompress said bushing at its U-bend between the first-uamed rim and theinner surface of said lid member.

2. A substantially leak-proof casing for a galvanic cell comprising abottom member having a sloping wall portion and a side wall, a lidmember fitted over said bottom member and having a side wall overlappingsaid first-named side wall, a substantially inverted U-sectionedinsulating bushing mounted on said first-named side wall with its U-bendriding on the rim thereof, said bushing having its outermost legincreasing in thickness from the U-bend positioned between the two sidewalls, and said second-named side wall being bent tightly against saidfirst-named side wall and having its rim portion bent over and crimpedagainst said sloping wall portion to maintain the said leg member andthe U-bent portion of said bushing in sealing compression with said lidmember and said bottom member.

3. A substantially leak-proof casing for a galvanic cell comprising abottom member having a side wall, a substantially inverted U-sectionedbushing mounted on said side walls with its U-bcnd riding on the rimthereof, said bushing having its outermost leg increasing in thicknessfrom the U-bend, a lid member fitted over said bottom member and havinga side wall overlapping said firstnamed side wall, one of said sidewalls flaring to facilitate mounting of the lid member on the bushingcarrying bottom member, and said side wall of said lid member being bentagainst the side wall of the bottom member to compress said leg of saidbushing therebetween and also being crimped against a portion of saidbottom member to maintain said compression and also to compress thebushing at its U-bend between the inner SUI- face of the lid member andthe first-named rim.

4. A substantially leak-proof casing for a galvanic cell comprising abottom member and a lid member fitted one into the other, said bottommember having a side wall, a substantially inverted U-sectionedinsulating bushing mounted on said side wall with its U-bend riding onthe rim of said wall, said lid member having anannular peripheral grooveto receive said U-bend of said bushing and also a side wall which ismounted over the outer leg of said bushing, said last-named side wallbeing bent aganist said first-named side wall and also having its rimportion crimped against said bottom member to maintain said leg memberof said bushing under compression between said side walls and its U-bend under compression within said groove.

5. A substantially leak-proof casing for a galvanic cell comprising abottom member and a lid member fitted one into the other, said bottommember having a side wall, a substantially inverted U-sectionedinsulating bushing mounted on said side wall with its U-bend riding onthe rim of said wall, said lid member having an annular internalperipheral groove to receive said U-bend of said bushing and said rim,and also a side wall which is positioned externally of the outer leg ofsaid bushing and overlaps the first-named side wall, said outer bushingleg increasing in thickness outwardly from said U- bend and lyingbetween said side walls, said side wall of said lid being bent againstsaid side wall of said bottom member and also having its rim portioncrimped against said bottom member to maintain said leg member of saidbushing under sealing compression between said side walls and the U-bentportion of the bushing under compression in said groove.

6. A galvanic cell comprising a substantially leakproof casing includinga bottom member containing superposed active materials with a separatortherebetween and having a side wall, a substantially invertedU-sectioned bushing mounted on said side wall with its U-bend riding onthe rim of said wall and having an annular flange on its innermost legabutting said separator and having its outer leg increasing in thicknessoutwardly from said U-bend, a lid member having a groove to receive saidU bend and a side wall overlying said outer leg and bent against saidfirst-named side wall to compress said outer leg between said two sidewalls and the side wall of said lid member having its rim portion bentand crimped about said bottom to compress and maintain the U-bentportion of said bushing within said groove.

References Cited in the file of this patent UNITED STATES PATENTS2,174,437 Collins Sept. 26, 1939 2,499,239 Williams Feb. 28, 19502,591,532 Fox Apr. 1, 1952 2,707,199 Ruben Apr. 26, 1955

